Collaborative Research: Rapic Climate Change due to Sea Ice Dynamics in the North Atlantic and Arctic Oceans

该项目的重点是研究由格陵兰冰芯记录的丹斯加德-奥施格(D-O)事件引起的北大西洋和北冰洋海冰面积变化所驱动的快速气候变化。最近的一项模拟研究表明，海冰的适度减少可以解释格陵兰冰芯记录的温度和积雪的突然变化。这个项目将解决的科学问题是：1)为什么海冰面积突然变化；2)为什么新的状态持续了几个世纪，然后逐渐崩溃到原来的冰川状态；3)这如何解释其他地方的气候突然变化？研究人员在研究中将遵循这样一种假设，即耦合的热带气候系统中的突然重新配置是长期存在的，并通过大气或海洋环流的遥相关影响热带以外的气候，只需要温盐环流的轻微变化就能驱动海冰变化，导致格陵兰记录的大规模快速气候变化。研究生和本科生将在这个项目中发挥主要作用，结果将影响研究人员教授的海洋学、气候和气候变化、气候建模和应用数学等课程。该项目还代表了气候动态学家、古气候数据专家和气候建模专家之间的合作，为解决根本的古气候问题提供了一种坚实的跨学科方法。气候模拟和代理数据的协同作用预计将被证明在指导未来的模型开发方面有用。

The focus of this project is the study of rapid climate change driven by changes in sea ice extent in the North Atlantic and Arctic oceans, motivated by Dansgaard-Oeschger (D-O) events recorded in the Greenland ice cores. A recent modeling study suggests that a modest reduction in sea ice can account for the abrupt changes in temperature and snow accumulation recorded in the Greenland ice core. The science questions which this project will address are: 1) Why did the sea ice extent change suddenly; 2) Why did the new state persist for several centuries before gradually collapsing back to its original glacial state; and 3) How does this explain abrupt climate changes elsewhere? The investigators will be guided in their research by the hypothesis that abrupt reconfigurations in the coupled tropical climate system are long-lived and influence the climate outside of the tropics via teleconnections through the atmosphere or ocean circulation, requiring only a modest change in the thermohaline circulation to drive sea ice changes that cause the large rapid climate changes recorded in Greenland.Graduate and undergraduate students are to play major roles in this project, and the results will influence courses taught by the investigators in oceanography, climate and climate change, climate modeling, and applied math. The project also represents a collaboration between climate dynamicists, paleoclimate data experts, and climate modeling experts, providing a solid cross-disciplinary approach to address a fundamental paleoclimate issue. The synergy of climate modeling and proxy data is expected to prove useful in guiding future model development.